Imprinting mechanism

ABSTRACT

A cam operative mechanism for controlling the platen of a printing device to provide a uniform printing pressure on articles of varying thicknesses. The platen is normally springbiased in its printing stroke to impress the article to be printed against the print die. During such movement a wedge is moved beneath and into engagement with a pair of yieldable arms carried by the platen to impart an additional movement to the platen, whereby printing pressure is applied. Regardless of the thickness of the article to be printed, an equal printing pressure is effected by the wedge and the arms, carried by the platen, thereafter yield as the printing stroke is completed.

[54] IMPRINTING MECHANISM [72] Inventor: Harry F. Noller, Moraga, Calif.

[73] Assignee: The Singer Company, New York,

[22] Filed: Oct. 26, 1970 [21] Appl. No.: 84,092

[52] US. Cl. ..l01/287, 101/316, 101/318 [51] Int. Cl. ..B41f 1/00 [58] Field of Search ..101/316, 319, 318, 407, 287, 101/3, 4, 9, 269

[56] References Cited UNITED STATES PATENTS 3,451,335 6/1969 Cunningham 101/407 X 2,350,853 6/1944 Wheeler et a1. 101/287 2,348,929 5/1944 Saxby 101/318 3,601,047 8/1971 Waibel ..101/316 3,388,659 6/1968 l-lu; ..l0l/407X 2,925,773 2/1960 Kingsley ....101/407 X 3,411,438 11/1968 Reader et al ..101/407 X 2,645,996 7/1953 Krakenberg ..101/319 [451 Sept. 26, 1972 2,076,064 4/1937 Carlson ..101/318 2,633,798 4/1953 Sloan ..101/318 3,455,236 7/1969 Lewis 101/23 1,110,723 9/1914 Spiess ..l01/320 Primary Examinen-Robert E. Pulfrey Assistant Examiner-R. T. Rader AttorneyCharles R. Lepchinsky, Patrick J. Schlesinger, Warren P. Kujawa and Jay M. Cantor 5 7 ABSTRACT A cam operative mechanism for controlling the platen of a printing device to provide a uniform printing pres sure on articles of varying thicknesses. The platen is normally spring-biased in its printing stroke to impress the article to be printed against the print die. During such movement a wedge is moved beneath and into engagement with a pair of yieldable arms carried by the platen to impart an additional movement to the platen, whereby printing pressure is applied. Regardless of the thickness of the article to be printed, an equal printing pressure is effected by the wedge and the arms, carried by the platen, thereafter yield as the printing stroke is completed.

5 Claims, 6 Drawing Figures PAIENIEDsms I972 SHEET E OF 4 IMPRINTING MECHANISM BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to printing devices and more particularly to the imprinting mechanism of a postage machine for the printing of postage impressions on envelopes of varying thicknesses.

2. Description of the Prior Art In the prior art devices having stationery printing die plates, the platen is moved to effect printing contact of an envelope with the die plate. To control such movement of the platen, a pair of members are rocked about a common shaft during an imprinting stroke, as disclosed in the copending application of Helmut K. Waibel, Ser. No. 831,327, filed June 9, 1969. One member is a driven member supporting the platen and the other is the driving member. As the driving member is rocked by the angular rotation of a cam, a compression spring interposed between the driving and driven member is effective to rock the driven member, moving the platen and an envelope carried thereby into contact with the printing die plate. Near the completion of the imprinting stroke, the spring is compressed to provide printing pressure for causing an impression to be made on the envelope. The angular rocking of the driven member by the driving member must be sufficient to enable the compression spring todevelop adequate imprinting force for the thinnest envelope; For greater thicknesses of stuffed envelopes, the compression of the spring begins sooner in the operating stroke and continues for the full stroke. Thus, the thicker the envelope the greater the imprinting force to beapplied and the greater the energy required to operate the machine. The primary object of the present invention is to overcome this, as well as other disadvantages of the prior art.

SUMMARY OF THE INVENTION According to the present invention, a printing device for printing documents of varying thicknesses comprises a framework in which a stationary printing die plate is mounted for printing contact by a document. A platen means is movable from a normally inactive position to effect contact of the document with the die plate. Upon movement of the platen and the contact of the document with the die plate, a pressure control device is moved by a power driven mechanism in a plane transversely of and at a right angle to the path of movement of the platen. During such movement, the pressure control device engages a yieldable means carried by the platen to apply a printing pressure to the platen for the taking of an impression from the die plate.

The nonsupported end of the yieldable means is normally angularly biased relative to the path of movement of the platen and in a direction opposed to the direction of movement of the pressure control device. As the platen moves the document into printing contact with the die plate, the thickness of the document determines the position of the nonsupported end of the yieldable means relative to the place of movement of the pres-' sure control device. As the pressure control device is then moved in an active direction, it engages the nonsupported end of the yieldable means (sooner or later) in accordance with the thickness of the document.

Continued movement of the pressure control device moves the yieldable means from its normally biased position through a center position causing a momentary printing pressure to be applied to the document while in contact with the die plate.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional elevational view of a portion of a postage machine showing the platen control mechanism;

FIG. 2 is a frontal, elevational view of the postage machine with the covers removed to show the platen control mechanism;

FIG. 3 is a fragmentary sectional elevational view of a postage machine showing the platen and the pressure control mechanism therefor, the view being taken on the plane indicated by line 3-3 in FIG. 2;

FIG. 4 is a fragmentary right side elevational view of the postage machine, showing one of similar pairs of parallel linkages for controlling movement of the platen;

FIG. 5 is an isometric projection showing the cam control means; and I FIG. 6 is a fragmentary sectional elevational view of a postage machine showing the actuated position of the platen.

Referring to FIGS. 1 and 2, a printing die 10 is mounted in a stationary position within the framework of the machine, supported between side frames 11 and 12 which are secured on a base plate 13. The printing die 10 includes the usual postal indicium l4 and value die surfaces, such as provided in known metered mailing machines, for the printing of postage impressions surface of the flexible pad 16 is flush with the top surface of the envelope table 18 to enable the emplacement of an envelope E thereon.

At its ends, the frame 17 of the platen 15 is provided with a pair of similar depending arms 22 and 23, respectively, the arms 22 and 23 (FIG. 2) being disposed in spaced parallel relationship to the inner surface of the corresponding frame members 11 and 12. At its lower end, each depending arm 22 and 23 carries respective laterally projecting pins 24 and 25 secured thereon. At its upper end, each of the arms 22 and 23 supports the respective end portions of a shaft 26 which is also supported, intermediate its ends, in a pair of spaced ears 27 and 28 integrally formed or otherwise secured to the lower surface of the frame 17 of the platen 15. The axis of the shaft 26 lies in a plane parallel with the top planar surface of the flexible pad 16 of the platen 15 and is also axially parallel to the axially aligned pins 24 and 25 carried by respective arms 22 and 23.

Each pin 24 and 25 projects through a suitable vertical slot in each of respective frame members 11 and 12 to pivotally support one end of a pair of lever arms,

similar to the arm 29 in FIG. 4. At its other end, each of the lever arms 29 is rockably supported on a pin, similar to pin 30 (FIGS. 1 and 4), carried by the respec tive frame members 11 and 12. Each end portion of the shaft 26 extends beyond the respective depending arms 22 and 23 of the platen 15 through the vertical slot in the frame members 1 1 and 12, respectively, to pivotally support the hook end of similar lever arms, identical to lever arm 31, as seen in FIG. 4. At its other end, each of lever arms 31 is rockably mounted on pins carried by frame members 11 and 12, such as pin 32 supporting lever arm 31 on frame member 11, as seen in FIG. 4. It will be noted that the lengthwise center-to-center dimension of the mounting holes of each of the lever arms 29 and 31 is identical. Also, the axial spacing between shaft 26 and pins 24 and 25 is identical to the axial spacing between the pins 30 and 32 on frame members 11 and 12. Thus, it can be seen that upon a rocking motion of the lever arms 29 and 31 of each pair of arms about the corresponding pins 30 and 32, the platen frame 17 is moved in a vertical path with the planar surface of the flexible pad 16 of the platen l maintained in a plane parallel to the face of the indicium plate 14. Normally, the platen is urged upwardly in its vertical path by means of a pair of relatively strong springs 36 which are under tension and disposed within suitable vertical openings within the frame members 11 and 12, such as the opening 37 shown in FIG. 4. Each spring 36 is secured at one end in an aperture in respective side frame members 11 and 12 at the top of the corresponding opening 37 and, at its other end, each spring is engaged in an aperture in the corresponding lever arm 31 of the pair of platen support arms 29 and 31.

At each end, shaft 26 carries one of a pair of rollers 38 which serve as spacers between lever arms 31 and respective platen arms 22 and 23. The rollers 38 are engaged by each of a pair of lever arms, similar to the arm 39 shown in FIG. 4. As seen in FIGS. 2 and 4, each of the lever arms 39 is secured on a shaft 40, journalled at its respective ends in side frame members 11 and 12. One of the lever arms 39 is disposed adjacent and between the depending arm 22 of the platen l5 and side frame member 11, while the other lever arm 39 is disposed between the depending arm 23 of the platen and the corresponding side frame member 12. Normally, the lever arms 39 serve to retain the platen 15 in the at rest position shown in FIGS. 1, 2, 3 and 4 whereby springs 36 are maintained under tension. Upon clockwise rocking movement of the lever arms 39, as viewed in FIG. 4, the springs 36 immediately bias the platen 15 upwardly to move an envelope E placed thereon into contact with the postage indicium 14.

For a postage imprinting operation, the depression of a control key 41 (FIGS. 1, 2 and 4) effects the energization of an electric motor (not shown) and the engagement of a conventional single cycle clutch, such as that shown and described in US. Pat. No. 2,935,254 issued to G. Plunkett, note Column 5, lines 36-51. During each cycle of machine operation, an ink roller 42 passes across the printing face of the indicium plate 14 followed by a vertical movement of the platen 15 to move an envelope E upwardly into contact with the indicium plate 14. Following such contact of the envelope E with the indicium plate 14, a tapered or wedge-shaped member 43 is moved to the left, as viewed in FIG. 1, beneath the platen 15 to cause a pressure to be applied to the platen 15 for the taking of a postage impression from the indicium plate 14, as will be hereinafter described.

Control key 41 is secured on one end of a lever arm 44, the other end of which is rockably supported upon the reduced diametral extension 45 of a spacer rod 46 disposed between side frame plates 11 and 12 (FIG. 2). The key lever arm 44 is guided in its movement by means of a plate 47 secured in spaced relationship on side frame member 11 by any suitable means, such as screws 48. Normally, the control key 41 is biased upwardly to its inoperative position by a spring 49 secured at its one end on a laterally disposed ear on the guide plate 47 and, at its other end, on a pin carried by the lever arm 44.

Immediately upon depression of the control key 41, the camming surface of a depending ear 53 (FIG. 1), carried by the lever arm 44, rocks the control arm 54 of a normally open Micro-switch 55 thereby closing the switch which is secured on the outer surface of the side frame member 11. As the control arm 54 is actuated to close Micro-switch 55, energization of the motor is effected and, by means of. suitable gearing, rotation is imparted to a gear 56 rotatably mounted on the right hand end of a drive shaft 57 journalled in the side frame members 11 and 12 (FIG. 2). The single cycle clutch of well-known construction is secured on the shaft 57 and is adapted for driving engagement with the rotating gear 56, upon engagement of the clutch by the depression of the control key 41.

Immediately upon engagement of the cyclically operable clutch and rotation of the drive shaft 57, means become effective to maintain the Micro-switch 55 closed for the duration of the cycle of machine operation. For this purpose, a cam 58 (FIG. 5) is secured on the drive shaft 57 and has peripheral contact with a roller 59 secured on the lower end of a sectorial follower 60 rockably mounted on a shaft 61 (FIGS. 1, 2 and 5), suitably journalled in side frame plates 11 and 12. Upon rotation of shaft57, the cam 58 becomes effective to rock the cam follower 60 clockwise from the normally inactive position shown in FIGS. 1 and 5 to move the peripheral surface of the sector portion 62 into engagement with the laterally projecting ear 63 of the switch control arm 54 to maintain Micro-switch 55 in its closed condition. Thus, the motor remains energized to complete the cycle of rotation of the drive shaft 57. The follower roller 59 is retained in engagement with the peripheral edge surface of the cam 58 by means of a spring 64 supported at its one end on a pin 65 carried by the sectorial follower 60 and secured at its other end in the framework of the machine.

During the initial rotation of drive shaft 57, one cam 70 of a series of cams 70, 71 and 72, all of which cams are secured on drive shaft 57, is effective to raise the ink roller 42 from a normally inactive position into rolling engagement with the indicium plate 14. Thereafter, the roller is moved across the plate to an interim inactive position where it is retained for the ensuing or 270 of the machine operating cycle.

lnking roller 42 (FIGS. 1 and 2) is carried by a shaft 73 extending transversely of the machine and supported for rotationin a pair of upturned parallel ears 74 of an ink tray, generally indicated at 75. At each end, shaft 73 is extended to rotatably support one of a pair of similar rollers 76 for a purpose to be hereinafter described. At the respective ends of the ink tray 75, and along the rear of the tray, a pair of U-shaped brackets 77 (FIGS. 1, 3 and 4) are formed in spaced relation thereon and serve to removably retain an ink impregnated cartridge 78 in place within the tray 75. The cartridge 78 extends lengthwise of the tray 75 and is resiliently maintained in contact with the surface of the inking roller 42 by suitable springs (not shown) disposed between the web of the brackets 77 and the cartridge 78. Intermediate the ends of the tray, and

between the U shaped brackets 77, the bottom plate of the tray is extended rearwardly and carries a flange 79 (FIGS. 3, 4 and 6) formed upwardly at a right angle thereto. The flange 79 serves to rockably support the inking tray 75 on a pin 80 carried by the upper hooklike extension of a plate 81 supported for rocking motion on a shaft 82 secured at its ends in frame members 11 and 12. Flange 79 is contiguous with the surface of plate 81 and at its rearwardly extended and angularly downwardly formed end, carries a laterally projecting pin 86 (FIGS. 1 and 3) engaging the bottom of an arcuately formed notch 87 in plate'81. Normally, the inking roller 42 is maintained out of engagement with the indicium plate 14 by the yieldable retention of pin 86 with the shoulder formed by the arcuate notch 87. For this purpose, pin 86 supports one end of a spring 88, the other end of which is secured on the transfer shaft 82.

Plate 81 and ink tray 75 carried thereby are normally urged to the inactive position shown in FIG. 1 by means of a spring 89 secured at its one end in a suitable aperture in the plate 81 and supported at its other end on a downwardly projecting pin 90 carried by the envelope table 18. In the inactive position of the ink tray 75, the inking roller 42 is forwardly of and out of engagement with, the indicium plate 14.

As stated above, during the initial 90 rotation of the cam 70 (FIG. 1), inking roller 42 is rocked upwardly into contact with the printing face'of the indicium plate 14 and is thereafter moved to the left or rearwardly of the machine, across the printing surface. For this purpose, a link 91 is-pivotally connected at its one end at 92 to the plate 81 and at its other end is pivotally supported on a pin 93 secured to the lower end of an angularly formed follower arm 94. Follower arm 94 is pivotally supported upon shaft 61 and is normally biased in a counter-clockwise direction by means of spring 89 to maintain a roller 95 on arm 94 in contact with the cam 70.

Uponcompletion of the initial 90 of rotation .of the cam 70, the pair of rollers 76 (FIG. 2) carried by the inking roller shaft 73 engage the lower edge su'rface 96 of the upper portion of the throat 97 formed in each side frame plate 11 and 12, rocking the ink tray 75 clockwise (FIG. 1) about the pin 80 on plate 81 against the urgency of the spring 88. At this time, the ink tray 75 has been moved to the left in FIG. 1 to its interim position as seenin FIG. 6, where it remains during the ensuing 180 rotation of the cam 70. In its interim position, the ink tray 75 andinking roller 42 are clear of the indicium plate 14 so that an envelope E may be moved by the platen 15 into printing contact with the indicium plate.

Immediately following the initial 90 rotation of drive shaft 57 and, therefore, cam 70, cam 71 becomes effective to release platen 15 to the influence of the pair of springs 36, whereby an envelope to be postmarked is moved into printing contact with the inked indicium plate 14. To this end, an arm 104 (FIGS. 1 and 3) is secured on transverse shaft which shaft, at its ends, carries the pair of lever arms 39, secured thereon and normally adapted to retain platen 15 in its normally inactive position shown in FIG. 4. At its free end, arm 104 pivotally supports one end of a link 105 at 106, the other end of the link having a pin 107 secured thereon and engaged in a suitable aperture in the lower end of an angularly formed follower arm 108 which is rockably supported on shaft 61. The pair of springs 36 serve through lever arms 31, shaft 26 and pawl arms 39 to resiliently retain a roller: 109 secured on follower arm 108 in engagement with the peripheral edge of the cam 71. The cam 71 and its follower 108 are effective to enable the springs 36 to retain the platen 15 in its raised position, whereby the envelope E is held in printing contact with the indicium plate 14.

Immediately following the vertical rise of the platen 15 and contact of envelope E with the postage indicium plate 14, the wedge 43 (FIGS. 1, 2 and 3) is moved to the left in FIG. 1 or to the right in FIG. 3 in a horizontal path transversely of and intersecting the path of movement of the platen 15. During this movement of the wedge 43, means are brought into play to apply a pressure to the platen 15 to cause a postage impression to be made on the envelope E irrespective of the thickness of the envelope.

Wedge 43 is cast or otherwise formed of a light weight material, preferably aluminum, and is supported by means of a pair of rollers 110 for movement from the front toward the rear of the machine on base 13. Rollers 110 are mounted for rotation on the respective ends of a shaft 114 carried by the wedge 43 extending lengthwise thereof and axially parallel to the shaft 26, by means of which the movement of the platen 15 is controlled. The taper of the wedge 43 is in the direction of movement of the wedge to active position, the lower surface of the wedge being spaced slightly above and parallel with the base plate 13. The top surface of the wedge 43 has an inclination of approximately 20relative to the base 13 and is preferably covered by a plate 115 of a substantially wear-resistant material such as steel, which is secured thereto. Normally, a spring 116, having one end secured on a pin 117 secured on base plate 13 and its other end supported on shaft 1 14, intermediate the length of the shaft 114 and wedge 43, serves to resiliently retain the wedge 43 in the inactive position shown in FIGS. 1 and 3.

Following the movement of the ink tray 75 and inking roller 42 to the position shown in FIG. 6 and immediately following the release of the platen 15 to its raised position, under the influence of the relatively strong springs 36, cam 72 becomes effective in its initial of rotation (FIG. 1) to movethe wedge 43 to the left from the normally inactive position shown in FIG. 1 or to the right from its inactive position shown in FIG. 3 to the fully moved position indicated by phantom line in FIG. 6. To this end, a-pair of similar links 118 and 119 are secured together for approximately half their length by any suitable means, such as rivets 120, and the left-hand end thereof (FIG. 1) is connected by means of a pin 121 to the lower end of a follower arm 122, rockably supported on shaft 61. The other end portion of the links 118 and 119 are laterally offset in opposition, one to the other, to form a yoke, the offset ends of which are supported on the respective ends of the shaft 114. In order to lend stability to the wedge 43 in its reciprocatory movement on the machine base 13, the offset end portions of the links 118 and 119, in addition to being supported on shaft 114, are further secured to the wedge 43 by any suitable means such as screws 123. Since the spring 1 16 normally biases wedge 43 to the right (FIG. 1) its influence also serves to retain a roller 124, carried by follower arm 122, in engagement with the peripheral edge of cam 72 for control of the movement of the wedge to active position.

As the wedge 43 moves to the left, as viewed in FIG. 1, or the right as seen in FIG. 3, the top surface of the plate 115 engages a pair of rollers, similar to roller 125 (FIGS. 3 and 6), mounted for rotation on suitable pins 126 carried by similar spaced parallel arms 130 rockably supported on shaft 26. Each arm 130 is positioned adjacent a corresponding one of the pair of ears 27 and 28 formed as an integral part of the platen frame 17 (FIG. 2). Normally, each arm 130 is biased clockwise (FIGS. 3 and 6) or counterclockwise (FIG. 1) by means of associated springs 131, each spring being supported at its lower end on the extended end portion of the roller support pin 126 of the corresponding arm 130. At its upper end, each spring 131 is secured on a pin 132 carried by each of a corresponding one of a pair of depending lobes 133 integrally formed on platen frame 17 (FIG. 2).

The arms 130 and rollers 125 carried thereby are normally biased to an angular position left of a vertical center line through the axis of shaft 26 (FIGS. 3 and 6) and perpendicular to the base 13, such a position being determined by the spring biased engagement of the arms with corresponding adjustable limit stops 134. Each limit stop 134 is threaded for adjustment into each lobe 133 and following its adjustment is locked in position by a lock nut 135.

For the printing of a postmark on a letter of minimum thickness, as exemplified in FIG. 6, and following the spring influenced movement of the platen to effect printing contact of the envelope E with the indicium plate 14, the wedge 43 is moved by the cam 72 to the active position. In the full line position of the wedge, as shown in FIG. 6, the surface of the plate 115 engages rollers 125 carried by the arms 130. Upon continued movement of the wedge 43 to the right, to the phantom line position in FIG. 6, the arms 130 are rocked counter-clockwise as the frictional point of contact of the plate 115 with rollers 125 moves to and through the vertical center line position. In the passing of such a point of contact through center, the platen frame 17 is raised an extent determined by the selective adjustment of the limit stops 134 and the normal angular position of the arms 130 relative to the vertical center line through the axis of the shaft 26. In the position of the arms 130, as shown in full line in FIG. 6, the platen frame 17 is moved upwardly by the wedge 43 approximately one-sixteenth of an inch.

The platen 15 will be raised an additional one-sixteenth of an inch for the printing of a postmark on all envelopes irrespective of their thickness. For the imprinting of an envelope of an envelope of a thickness greater than that of the envelope shown in FIG. 6, the rollers 125 are engaged by the wedge 43 at a point on the surface of the plate determined by the thickness of the envelope and the relative height of the platen, as printing contact is made with the indicium plate 14. Stated otherwise, the greater the thickness of an envelope, the less the extent of rise of the platen to effect contact of the envelope with the indicium plate. For an envelope of maximum thickness, the platen l5 and, therefore, rollers will rise only a slight extent and the top surface of the wedge 43 will engage the rollers immediately upon movement of the wedge as it intersects the path of travel of the platen. Due to the angular disposition of the arms relative to the path of travel of the platen and in a direction opposing the direction of movement of the wedge and upon engagement of the inclined surface of the wedge with the rol lers 125, the rollers are frictionally seized momentarily so that the arms 130 are rocked through and beyond the vertical center line by the continued motion of the wedge 43.

During the final one-sixteenth ofan inch movement of the platen 15, i.e., the pressure imprinting part of the cycle of movement of the platen, the springy elastomeric material of which the pad 16 is formed, will yield while providing a relatively constant imprinting pressure of the envelope against the indicium plate 14. It will be noted that the greater the angular disposition of the arms 130, the later the inclined surface of the wedge 43 engages the rollers 125 during the movement of the wedge. This necessarily means that the arms 130 are thereafter rocked in a greater are for passage of the rollers 125 through center and the printing pressure is increased accordingly. Irrespective of the thickness of an envelope to be postmarked, the printing pressure will be constant for any given normally adjusted position of the arms 130. During the movement of the wedge to the active position and following the engagement of the top surface of the wedge with the rollers 125, the arms 130 are rocked counter-clockwise (FIG. 6) beyond center sufficiently to permit the arms to collapse, thereby enabling a release of the printing pressure.

Immediately following of the cyclic rotation of drive shaft 57, cam 72 releases the wedge 43 to the influence of its spring 1 16, for restoration of the wedge to its normally inactive position. Thereafter cam 71 becomes effective to restore the platen 15 to its at rest position against the influence of the relatively strong springs 36. During the final 90 of the cycle of rotation of drive shaft 57, cam 70 effects the release of the ink tray 75 and roller 42 to its normally inactive position under the influence of the spring 89. Following the restoration of the wedge 43, the platen 15 and the ink tray 75 into their respective inactive positions, and at approximately 315 of the cycle of rotation of the drive shaft 57, cam 58 enables a counter-clockwise rocking of the sectorial follower 60 (FIG. 1) to the influence of its spring 64 whereby switch control arm 54 is released opening the switch 55 to terminate the operation and the follower roller 59, in cooperation with cam 58 (FIG. 5) is effective to centralize drive shaft 57.

What is claimed is:

l. A printing device comprising:

a framework;

a stationary printing die plate mounted in said framework;

a platen means having a planar surface for effecting contact of an article to be printed with said die plate when raised from an inactive position to an active position;

means for moving said platen means from said inactive position to said active position; and

platen pressure means for applying printing pressure to said platen means when in said active position, said platen pressure means including:

a wedge-shaped member having a tapered surface movable along a path from an inoperative to an operative position, said path being substantially transverse to the path of travel of said platen means;

a pair of arms pivotally mounted on said platen means, each said arm having a free end adapted to contact said tapered surface as said wedge-shaped member travels to said operative position;

yieldable means for biasing each of said arms to a predetermined angular position relative to a center line perpendicular to said planar surface of said platen means and in a direction toward said inoperative position; and

means for moving said wedge-shaped member between said inoperative and said operative positions when said platen means is in said active position so that said free ends contact said tapered surface, movement of said wedge-shaped member toward said operative position after said contact causing said arms to pivot from said predetermined angular position toward said operative position of said wedge-shaped member thereby applying printing pressure to said platen means.

2. The apparatus of claim 1 wherein said yieldable means includes means for adjusting said predetermined angular position of said arms.

3. The apparatus of claim 1 wherein each of said free ends of said pair of arms is provided with a rotatable roller for contacting said tapered surface.

4. The apparatus of claim 1 wherein said means for moving said platen means includes first and second pairs of spaced arms for supporting said platen means, each said pair rockably mounted for parallel motion in said framework to maintain said planar surface of said platen means parallel to said die plate; bias means coupled to at least one of said spaced arms and said framework for urging said platen means toward said active position; lever means for normally retaining said platen means in said inactive position; and control means for moving said lever means to permit said bias means to move said platen means to said active position.

5. The apparatus of claim 1 further including roller means for supporting said wedge-shaped member. 

1. A printing device comprising: a framework; a stationary printing die plate mounted in said framework; a platen means having a planar surface for effecting contact of an article to be printed with said die plate when raised from an inactive position to an active position; means for moving said platen means from said inactive position to said active position; and platen pressure means for applying printing pressure to said platen means when in said active position, said platen pressure means including: a wedge-shaped member having a tapered surface movable along a path from an inoperative to an operative position, said path being substantially transverse to the path of travel of said platen means; a pair of arms pivotally mounted on said platen means, each said arm having a free end adapted to contact said tapered surface as said wedge-shaped member travels to said operative position; yieldable means for biasing each of said arms to a predetermined angular position relative to a center line perpendicular to said planar surface of said platen means and in a direction toward said inoperative position; and means for moving said wedge-shaped member between said inoperative and said operative positions when said platen means is in said active position so that said free ends contact said tapered surface, movement of said wedge-shaped member toward said operative position after said contact causing said arms to pivot from said predetermined angular position toward said operative position of said wedge-shaped member thereby applying printing pressure to said platen means.
 2. The apparatus of claim 1 wherein said yieldable means includes means for adjusting said predetermined angular position of said arms.
 3. The apparatus of claim 1 wherein each of said free ends of said pair of arms is provided with a rotatable roller for contacting said tapered surface.
 4. The apparatus of claim 1 wherein said means for moving said platen means includes first and second pairs of spaced arms for supporting said platen means, each said pair rockably mounted for parallel motion in said framework to maintain said planar surface of said platen means parallel to said die plate; bias means coupled to at least one of said spaced arms and said framework for urging said platen means toward said active position; lever means for normally retaining said platen means in said inactive position; and control means for moving said lever means to permit said bias means to move said platen means to said active position.
 5. The apparatus of claim 1 further including roller means for supporting said wedge-shaped member. 